- Fantastic Racism: The demi-humans are victims of this. Celty claims that dullahans face this too, which is why she tries to make sure that she treats Anri fairly.
- Cat Girl: Anri and Mika.
- Cuddle Bug: Mairu and Kururi love to glomp and cuddle Aoba.
- Little Bit Beastly: Mikado (dog), Masaomi (parakeet), Anri (cat), Aoba (fox), Mika (cat), Walker (raccoon), and a few others who are mentioned but don't physically show up.
- Winged Humanoid: Masaomi. Flying is the one thing he loves most in the world.
- Bad Boss: Izaya toward Masaomi, Namie towards Mika.
- Benevolent Boss: Shinra and Celty, perhaps a little too much toward Anri. Also, Shizuo toward Mikado.
- Shipping: Mikado/Anri, Masaomi/Saki, Shinra/Celty, Shizuo/Vorona, Walker/Erika, Seiji/Mika and Mairu/Aoba/Kururi.
- Star-Crossed Lovers: Walker and Erika, Saki and Masaomi and Mika and Seiji.
- The Woobie: Masaomi.
- Twin Threesome Fantasy: Mairu and Kururi consider Aoba to be their "playmate". Izaya interprets this as code for sex.
- OT3: Mairu, Aoba and Kururi.
- Yakuza Princess: Erika.
Darth Wiki / The Depths Of The City
The Depths of the City is an unpublished AU Durarara!! fanfiction by CJ Croen 1393In this AU, there are some humans born with animal-like qualities. They are called "demi-humans" and are treated pretty well by some, crappily by others and essentially looked down on by society, often being hired as domestic help. Mikado Ryugamine, a dog demi-human, enters Ikebukuro to attend a local high-school, and his best friend, Masaomi Kida a parakeet demi-human finds him work with Shizuo Heiwajima. Mikado meets other demi-humans later, like Anri Sonohara, a cat demi-human who works (in the loosest sense of the word) for Shinra and Celty Kishitani, Walker Yumasaki, a raccoon who works for the wealthy Karisawa family, Aoba Kuronuma, a fox who works for the Oriharas with Masaomi, and Mika Harima, a cat who works for the Yagiri family.But Mikado begins to notice that Masaomi is hiding something and won't tell him about it. When he finds out, Mikado realizes that something must be done to raise awareness of how demi-humans are being mistreated.Basically, this is supposed to be a good version of For Your Eyes Only.